<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="./lib/vue-2.4.0.js"></script>
    <link rel="stylesheet" href="./lib/bootstrap-3.3.7.css">
    <style>
        .ball {
            width: 50px;
            height: 50px;
            border-radius: 50%;
            background-color: red;
        }
    </style>
</head>

<body>
    <div id="app">

        <button type="button" class="btn btn-primary" @click="show= !show">惺惺</button>

        <transition @before-enter="beforeEnter" @enter="enter" @after-enter="afterEnter">
            <div class="ball" v-if="show"></div>
        </transition>

    </div>

    <script>
        var vm = new Vue({
            el: '#app',
            data: {
                show: false
            },
            methods: {
                beforeEnter(el) {
                    el.style.transform = "translate(0, 0)";
                },
                enter(el, done) {
                    // done()表示立即执行afterEnter
                    el.offsetWidth
                    el.style.transform = "translate(100px, 200px)";
                    el.style.transition = "all 2s ease";
                    done()
                },
                afterEnter(el) {
                    this.show = !this.show
                }
            },
        })
    </script>
</body>

</html>